Tensioning device



June 24, 1958 J. H. BoLLEs ETAL 2,840,768

TENsIoNING DEVICE Filed July 29, 1953 2 Sheets-Sheet 1 y JNVENToRs JUL/US H. 801155 LYNA/V A. H/Lf June 24,1958 J. H. BULLES Em 2,840,768

TENSIONING DEVICE Filed July 29, 1953 2 Sheets-Sheet 2 IN VEN TORS JUL/U5 H. Bllf L YMAN A. RICE TENsIoNING DEVICE Julius H. Belles and Lyman A.. Rice, Anderson, Ind., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application July 29, 1953, Serial No. 371,133

3 Claims. (Cl. S17-198) This invention relates to improvements in a tension device for a regulator for controlling an electrical device and more particularly to a voltage regulator for controlling the electrical output of a generating means.

In general the type of controller for an automobile generator for producing current for recharging 'la storage battery includes an assembly of units consisting of a cutout, a current regulator and a voltage regulator all mounted on the same support or base and having a protective cover enclosing same. lt is frequently desirable to change the amount of current which is supplied to the storage battery depending, for instance, upon summer or winter driving yand also depending somewhat upon the amount of day and night driving of the automobile. The most common method of adjusting the regulators heretofore has been to remove the protecting cover and by suitable tools the operator would alter the tension vor position of the spring of the voltage regulator. Such adjustments are rather diiiicult, especially by unskilled mechanics as it is impossible to t-ell whether the altered tension of the spring is suiiicient or too much. The purpose of the present invention is to provide non-critical means of altering the current or voltage setting without removing the protective cover.

An object of the present invention is 'to provide manually operable means for closely adjusting the regulator in an easy manner.

Another object of the present invention is to provide fine adjustable means for the voltage regulator which may extend through an enclosure and move a member within the enclosure for controlling the spring tension of the voltage regulator.

Further objects and advantages of the present invention will be apparent from the following description reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

ln the drawings:

Fig. l is a vsectional view of the cover and side `elevational view of the improved tension device used on a voltage regulator.

Fig. 2 is an end view taken on line 2-2 of Fig. l.

Fig. 3 is a perspective view `of the tension device as used on a voltage regulator.

Referring to the drawings, a voltage regulator or circuit breaker 20 is mounted on a base 21 from which extend side flanges 22 and 23 and end flanges 24. The end flanges 24 terminate in notched ears 25 adapted to receive suitable securing devices, not shown, for attaching the base to any suitable support. The side flange 22 has suitable spaced openings to receive terminal. plates, one for each instrument mounted on the base. One of the terminal plates 26, for the voltage regulator, is insulatingly supported from the base 21 by insulating strips 27.

The base 21 carries a magnet assembly 28 that includes a core 30 haing a pole piece 31 and a bracket 32 supporting a connector 33 to which one end Iof a winding `atent Ctitice Patented June 24, w58

M 34 is attached at 35. The connector 33 supports a fixed contact 36 which cooperates with a movable contact 37 carried by an armature plate 3S. The armature plate 38 has an arm 39 extending at right angles from the plane of the plate. The armature plate supports a spring hinge 40 and a plate 41. The armature plate 38, the hinge 4t), and the plate 41 are secured together by rivets 42. The spring hinge 40 extends beyond the plate 41 and has two spaced tongues 43 that are secured by rivets or by welding to spaced ears of a magnet frame 44 disposed adjacent to the magnet assembly. The magnet frame 44 includes an arm 45 secured to the base 21 by an extension of the core 30 which passes through an opening in the base and riveted against the underside of the base 21. The plate 41 is provided with a hook or spring seat 46 supporting one end 4of a spring 47, the other end of the spring is attached to a spring seat 48 of a movable bracket 5t), which moves parallel with an arm 51 of the magnet frame 44. When assembled as explained, the spring 47 urges the armature in a clockwise direction to maintain the contacts 36 and 37 in closed position with a predetermined force. The spring force by which the contacts 36, 37 are kept in engagement can be varied by the adjustment of spring 47 and thus determine the magnetic force `that must be developed in the magnet assembly for separating the contacts 36, 37.

Referring to Fig. 3 the bracket 50 is stamped from sheet metal and bent to form a U-shaped end to include a base 52 and spaced ears 53 and 54 having aligned apertures 55 and 56 respectively. The aperture 55 is larger than the aperture 56. The ear 53 has an extension 57 which has the hook 48 rigidly attached thereto. The other end of the extension 57 is notched at 58 to provide tines or prongs 61 which straddle an arm 62 of a bracket 65 of sheet metal.

The bracket has a base portion 66 provided at one end with outwardly extending ears 67 having tapped openings. One of the ears is bent slightly toward the other ears so that the tapped openings are sightly out of axial alignment. The other end or the base carries the arm 62 which is rst bent outwardly at right angles to the plane of the base 66 and then bent downwardly so 4that the arm is disposed in offset relation with the base portion 66 and spaced from arm 51 of the magnet frame to permit the tines or prongs 61 to straddle the arm 62 and guide the movable bracket S0 in its up and down movements as viewed in Fig. 3. The base 66 of the bracket 65 is secured to the arm 51 in any suitable manner. In the present instance the base is spot welded to the arm S1 as indicated at 70.

In the present instance the bracket 65 is located above the movable bracket 50, but it is is to be understood the bracket 65 could be located below the bracket with the arm extending upwardly. The tapped opening in the ears 67 receive a `screwdriver slotted screw 71 in binding relation. The lower end of the screw 71 has a plain .cylindrical portion 72 and a reduced extension 73 to provide a shoulder 74.

The tension of the spring may be varied, to modify the movement of the armature 38 by the adjusting screw 71. This is accomplished by having the shoulder 74 rest on the ear 54 so as to move bracket 5t) downwardly as the screw is threaded downward, as viewed in Fig. 3. Since the threads of the screw 71 have a binding effect with the threads of the tapped openings in ears 67 the screw 71 is held firmly in any adjusted position.

The armature carries the contact 37 for engagement with the contact 36. A tongue 75 is bent upwardly from the bracket 32 to provide a stop for the armature. As is obvious the stop 75 limits the movement of the armature toward the pole piece 31 of the core 30.

An important feature of the present invention is to Y of an automobile.

provide the screw 71 with the long extension 73 which will extend through an opening 80 of the base 21. A lever 81 can be attached to the extension 73 in any suitable manner and can be actuated by a hand orjtool from one end to the other in an opening or slot 82 in the side ange 23. The circuit controller is normally set at the factory to give satisfactory results for normal driving conditions. generally positioned in the mid portion of the slot. During operation of the voltage regulator, the voltage regulator limits the voltage in a charging circuit to a safe value thereby con-trolling the rate of thefgenerator in accordance with the requirements of the battery and the current consuming electrical units in operation. When the battery is lov;l the generator output is near maximum, but as the vbattery comes up to charge and other requirements are small the voltage regulator operates to limit the voltage thereby reducing the generator output. This protects the battery from Vovercharge and the electrical system from high voltage.

The voltage regulator as shown in the drawings consists of two windings 34 and 75. The voltage or shunt winding 75 consists of a plurality of turns of ne wire connected so that generator voltage is impressed upon it at all times. The series winding 34 is of fewer turns of heavy wire and carries the generator field current directly to ground when the contacts 36 and 37 are closed.

lt is frequently desirable to change the amount of current which is supplied to the storage battery depending upon, for example, summer or winter driving and also depending upon the amount of day and night driving When it is desired to increase the voltage, say one-half volt, the lever is turned in a clockwise direction as viewed in Fig. 3 until the lever engages the end of the slot 32. This operation increases the tension in spring thus increasing the voltage and if it is desired to decrease the voltage the lever is turned in a counterclockwise direction until the lever engages the opposite end of the slot 82. This operation decreases the tension of the spring thus lowering the voltage. The turning of the screw can be accomplished without removing the cover.V If further adjustment is necessary the cover is removed and lever must be removed from the extension.

The invention possesses certain advantages 'that eliminate removing the cover when it is desired to increase or decrease one-half volt; it elminates the most common method of adjustingvoltage regulator namely the method of bending a metal part by a tool to alter the tension of the spring 47. The act of bending a metal part to change the tension of the spring 47 is rather dicult because it may be necessary to repeat the bending operation many times before the desired tension in the spring is obtained. In the present invention the bending eiect between the screw 71 and the tapped ears 67 will permit very iine adjustments and thereby vary the tension of the spring and also adjust the armature 38 to operate in the desired manner. The regulating action of the regulator can be Very accurately maintained.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

The normal position of the lever is What is claimed is as follows:

1. In a circuit controller the combination comprising; a frame supporting a core surrounded by a winding; a tension spring for urging the armature away from the core; a pair of apertured threaded ears extending from said frame and tending to converge toward one another; a guide member extending from the frame; a floating member attached to one end of the spring and having a forked end straddling the guide member; and an adjusting screw threaded in said ears and journalled in apertures ot' another end of the oating member whereby rotation of the screw will vary the position of the oating member relative lto said frame for varying the tension of the spring on said armature.

2. In a circuit controller relay, the combination comprising; a base; a frame mounted on said base; a magnet carried by the frame; an armature positioned in operative relation to said magnet and hingedly mounted on said frame, a spring having oneend connected to said armature, a pair of apertured threaded ears extending from said frame and tending to converge toward one another, a screw threaded through the ears, means journaled on said screw and connected to the other end of said spring, said means being adjustably controlled by said screw whereby the action of the armature with respect 'to the magnet may be adjustably varied within predetermined limits; a cover for said baise for enclosing the parts associated with said frame; and means extending through said base for moving said screw relative to said frame from the exterior of said regulator after the cover is assembled to the base.

3. In a circuit controller, the combination comprising; a base; a cover for said base; a frame carried by said base; a magnet carried by the frame; an armature positioned in operative relation to said magnet and hingedly mounted on said frame; a pair of apertured, threaded ears extending from said frame, and tending to converge toward one another, a screw threaded through lthe ears; means movably journaled on said screw and resiliently connecting the armature with the screw, said means being adjustably lcontrolled by said screw whereby the action of the armature with respect to the magnet may be adjustably varied within predetermined limits when the cover is removed from said base; and means externally accessible to said cover and base for moving the screw when the cover and base are assembled; and limiting means carried by said base for limiting the adjustment of said screw by said external means. i

References Cited in the tile of this patent UNITED STATES PATENTS Switzerland J une 2l, 

